Field of the Invention
The present invention relates to an organic insulating material and a flexible display device including the same and, more particularly, to a flexible display device in which an organic insulating film including a new organic insulating material having a self-healing ability has been formed.
Discussion of the Related Art
A variety of display devices capable of reducing weight and volume, that is, disadvantages of a cathode ray tube (CRT), are recently being developed. Such display devices may include, for example, a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting display device (OLED). Furthermore, there is emerging a flexible display device that is fabricated to maintain display performance without a change although it is bent like paper using a flexible material, such as plastic, instead of an existing glass substrate not having flexibility.
The flexible display device is formed of a plurality of thin film transistor elements and organic insulating films. The organic insulating film includes a photosensitive resin composition formed of components, such as photo acryl (PAC), a binder, and a solvent. Acrylic resin has been commonly used as the binder. Conventional photosensitive resin has a problem that it is difficult to achieve high transmittance for an insulating layer because the photosensitive resin is colorized after hardening. Also the conventional photosensitive resin has a problem that volume is reduced after hardening. In order to suppress such colorization or volume reduction, a method of using a monomer not including a phenyl functional group or a method of increasing the glass transition temperature Tg of the organic insulating film is used. The methods are problematic in that the lifespan of a display device is reduced because a crack is generated in the organic insulating film if bending is generated in the completed display device and the generated crack is further grown over time.